Machine for molding articles from pulp.



F. W.'WATERMAN.

MACH'INE FROM MOLDING ARTICLES FROM PULP. MPLICAIION FILED MAR- 2.1917.

1,800,677. Patented Apr. 15,1919.

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F. W. WATERMAN.

MACHINE FROM MOLDING ARTICLES FROM PULP.

APPLICAHON FILED MAR.2,19I7- 1,300,677, Patented Apr. 15, 1919.

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MACHINE FROM MOLDING ARTICLES FROM PULP. APPLICAHON FILED MAR. 2. 1917.

Patented Apr. 15, 1919,

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FRANK W. WATERMAN, OF BALTIMORE, MARYLAND, ASSIGNOR TO KEYES FIBRE COMPANY, OF WATERVILLE, MAINE, A CORPORATION OF MAINE.

MACHINE FOR MOLDING ARTICLES FROM PULP.

Application filed March 2, 1917.

like characters on the drawing representing like parts.

This invention relates to improvements in machines for molding articles from pulp such as that disclosed in Patent No. 1,139,002 granted to me May 11, 1915, in which a series of traveling molds having separable mold faces are. supplied with a layer of pulp which is compressed between the mold faces .to form a molded article a In the apparatus disclosed in that patent, as well as'in all other pulp molding machines with which I am familiar, the mold members are subjected to heavycompression applied during a short interval in the travel of the mold so that the fluid content of the pulp is squeezed out quickly.

By thus forcing the fluid out of the pulp rapidly minute streams are formed which carry away solid particles of the pulp and produce thin places or at times even holes in the molded articles. Where the solid portions of the pulp are massed into lumps this rapid squeezing out of water fails to disintegrate the lumps thoroughly and leaves a hai'd spot or knot-like spot in the molded artic e.

The principal object of the present invention is to provide a molding machine with means for applying a gradually progres sively increasing pressure to the cooperating mold members during a considerable, that is to saya relatively long, portion of the travel of the mold so that the liquid content of the pulp will be gradually squeezed out and the solid particles will have time to rearrange themselves uniformly throughout the efiective area of the mold faces. y

By reason of this relatively slow expulsion of the fluid from the pulp the molded articles produced are of a superior quality having a more uniform and homogeneous character throughout and the surface of the articles present a much smoother appearance.

Another object of the invention is to pro- Specification of Letters Patent.

Patented Apr. 15, 1919.

Serial No. 151,880.

vide means for discharging flat molded articles, such as plates, from the molds without distortion. In machines for molding flat articles such as plates, it has heretofore been customary either to thrust the article from the mold by pressure upon its flat central portion or to lift it from the mold by a suction device applied to the central portionof the article. As a consequence the central ortion or base of the article is frequently bulged so that the molded articles do not have the same holding capacity and do not package readily.

My invention contemplates the removal of the article by pressure applied near its circumference, for example in removing plates from the mold the pressure is applied to the under surface of the inclined peripheral wall of the plate. I have found that by discharging the plate in this manner its central portion is not distorted and that the pressure applied to the marginal portion of the plate has no ill effect.

Other objects andfeatures of the invention will more fully appear from the following description and the accompanying drawings and will 'be particularly pointed out in the annexed claims.

In the drawings;

Figure l is a side elevation of a pulp molding machine embodying the preferred form of my invention, the vat being shown in section,

Fig. 2 is an end elevation of the same, a portion of the wall of the pulp vat being broken away,

Fig. 3 is mainly a vertical sectional view on an enlarged scale through one of the molds, its supporting arm and hub, certain portions being shown in elevation, and,

Fig. 4.- is a transverse sectional view through the compression member of the mold illustrating in connection therewith the means for discharging the molded article from it.

The invention illustrated in the drawing may be broadly described as comprising series of traveling molds having separable members provided With mold faces with means for supplying a layer of pulp to said mold faces and means for exerting a gradually progressively increasing compression upon said mold members during a considerable portion of the travel, one of the separable mold members of each of the series being provided with means acting upon the under surface of the peripheral portion of the molded article to discharge it from the mold.

' The preferred embodiment of the invention is disclosed in the accompanying drawings as applied to a machine of the type disclosed in my prior Patent No, 1,139,002 aforesaid which comprises a pulp receptacle 1 into which the receiving members 2 of a series of traveling molds successively dip. The receiving mold members are carried upon the ends or formed integral with hollow arms 3 which are radially attached to a central hub 4: which is keyed or otherwise rigidly secured upon a shaft 5 journaled in bearings in standards 6 which, as illustrated herein, are secured to the side Walls of the vat. It will, however, be understood that if the vat is sunken'beneath the floor the supporting standards may bemounted upon the floor in proximity to the side walls of the vat. A pulley 7 fixed upon the shaft serves to rotate it and the traveling mold members as will be readily understood.

Each of the mold supporting arms 3 is I hollow to form a suction passage. 8 which communicates with a port 9 in the hub 4 leading to one side thereof and which communicates during a portion of a revolution with a chamber from which the air has been partially or wholly exhausted. This construction is substantially like that disclosed in my prior patent aforesaid.

V In order to provide a machine of maximum capacity, and also to balance the machine so as to avoid lateral strains, the rea ring or cap 13 screwed upon the exteriorwall of the chamber 10.

In the operation of the machine the receiving mold sections are immersed in the pulp and suction applied tothe hollow arm- 3 so that layers'of pulp. will adhere to the oppositely disposed mold faces. -In View of the fact that the finer material is first deposited upon the mold faces by the suction and a smooth surface thereby formed, the perforated plates 11 and their overlying mesh 12 are dished outwardly to present their convex sides to the pulp solution so that the inner face of the plates will be smooth.

' The hollow supporting arm 3 preferably is -oflset and communicates substantially tangentially with the suction chamber 10, the formation being such that the offset portion will serve to catch and remove the liquid contained in the chamber of the-moldas the latter rises from the pulp vat. A compressed air pipe 14 which communicates with the suction chamber at the side opposite the offset portion of the arm 3 provides a means for releasin the molded articles from the mold receiving faces in'the manner-disclosed" in my prior patent aforesaid.

A pair of compression mold members 16 which are separable from the receiving mold members are mounted in cooperative relation with the oppositely disposed receiving mold members, each of the compression members being mounted upon a supporting arm 17' which is pivoted upon a stud 18 projecting'from a bracket or extension on the arm 3. A segmental gear 19 is operatively connected to each arm 17 and cooperates with -a reciprocatory rack 20. Each rack 20 is slidably mounted in a guide 21 supported upon the arm 3 and is provided with a roller or stud 22 which follows a cam track 23r'as the .arm rotates.

-In "order to support the cam disks 24: in cooperative relation to the mold carrier the cam disks are provided with sleeves 25 which loosely surround the shaft 5 and are coupled at their'outer ends 'to anchoring devices which preferably comprise segmental bushing sections adapted to fit into the standards 6 and form the lower halves of bearings for the shaft 5.

In the operation of the machine, the rotation of the arm 3 which supports all of the cooperating mold members causes the rollers 22 to follow the cam track 23. The cam tracks are so formed that as each successive mold member approaches the pulp inthe vat, the racks 21 are moved inwardly, or toward the axis, causing the arms'17 which carry the compression mold. members 16 to be raised away from the receiving mold enter the pulp within the vat.

mold faces with-a layer of pulp adhering thereto are removed from the vat the cam faces so thatv the receiving. mold faces only tracks 23 force the racks 20' outwardly there s.

by causing the segmental gear 19 to oscillate the arms 17 and force the compressionfaces heres to the receiving mold face.

The c'ompresslon mold members comprise faces which are substantial counterparts of,"

the mold faces 12 of the receiving mold face I A 2. Heretofore these compression mold faces have been formed with a central. movable portion by which the molded article was dismold face is so constructed as to have a pcripherally movable member adapted to be short distance from its margin, a peripheral groove to provide a guideway for a pcripheral portion 32 of the mold face. The outer wall of the groove is extended to form a flange 31 adapted in cooperation with the inner edge of the ring or cap 13 to shear off the material which extends beyond the periphery of the mold face. Both the central and peripheral portions of the mold face are perforated in the usual manner. ripheral portion 32 of the mold face is provided with a series of pins or studs 35 which extend through suitable apertures in the plate 29 and engage a discharging plate or spider 36 which has a solid central portion 37 and is normally actuated by sprlngs 38 to hold the peripheral mold member in molding position.

As illustrated in Fig. '4 of the drawing, the springs 38 are shown as seated near the periphery of the central portion of the compression mold face and act normally to force the spider 36 backward so that the peripheral mold member will be withdrawn 7 into the groove 31' and the mold properly assembled to cooperate with the receiving mold face to form a plate.

The back of the compression mold member is provided with a transverse inclined guideway for an impingingmember and has a central aperture 39 through which the impinging means may enter to engage the central portion 37 of the discharging plate or spider 3-6. a

A preferred form of impinging member which is illustrated herein comprises a spring actuated pin 4Lwhic h is telescopically mounted in an arm 41 depending from the sleeve 25 and projecting into the path of the body of the compression mold member. The pin 40 may conveniently be formed witha head 7 42 slidably fitting within a sleeve 43 which is adapted to be screwed into a socket 44 in the arm 41. A helical spring 45 of greater strength than the springs 38 bearing upon the base of the socket 44 and the head 42 of the pin normally holds the pin in extended position. I

In the operation of the machine the com pression mold member passes beneath the depending arm 41 and the end of the stud 40 extending thereover engages the inclined surface 46 upon said member and rides up upon it. The pin is thereby forced back- The peward against the compression of the spring 45 and retained in said position until the aperture 37 is reached, whereupon the pin is projected forward by the force of the spring and raps sharply upon the central portion 37 of the discharging disk 36. This forces the latter forward against the action of the springs 36 and projects the peripheral portion 32 of the compression mold face beyond its central portion, thereby detaching and discharging the molded article. Upon further movement of the compression mold member the pin 40 rides up the oppositely inclined surface 47 thus releasing the discharging spider 36 so that it is returned by the springs 38 to normal position and the peripheral portion of the mold face withdrawn into molding position.

a The back of the compression mold member desirably is provided with bosses 48 to receive studs carrying antifriction rollers 41) adapted to engage means for applying a gradually increasing pressure to the mold member. It will be noted that in the construction illustrated herein the receiving mold faces are upon' opposite sides of the central suction chamber 10 and the compression mold faces which cooperate with the receiving mold faces are consequently disposed opposite to each other. By reason of this construction compressive force applied to the oppositely disposed compression mold members may be utilized to force them equally toward the central mold receiving faces so that power applied in compressing the pulp between the pairs of mold faces will be equally balanced and no lateral strain placed upon the arm which carries the receiving mold member, consequently there will be no material vibration of the machine.

In the construction disclosed in my prior patent the compresive force was applied to the backs of the oppositely disposed compression mold members by a pair of spring actuated rollers carried by a frame extending upwardly from the walls of the vat. These rollers engaged sharply inclined surfaces upon the backs of the compression mold members and in the operation of the machine imposed a strong compressive force upon the mold members during a short interval in the. rotation of the molds.

laterally extended webs 53 of gradually increasing width downward to strengthen the 1 same against the lateral strains of the compression mechanism.

The means for applying compressive force to the compression members of the traveling mold desirably comprise two compressor I plates which conform to the path of the traveling mold and are forced against the same by gradually increasing pressure as the mold progresses along said plates. Where, as in the device illustrated 1n the drawing,

7 the molds travel in a circular path, the compressor plates 54 are arcuate in form and preferablyextend through approximately a quadrant. v

The compressor plates 54 desirably are yieldabl .mounted upon opposite sides of the pat of the molds and preferably are normally inclined to converge in the direction of movement of the molds. In order pose a progressively lncreasmg 51, said springs being mounted upon bolts or studs 62 which are anchored in the compression plates 54: and project through suitable apertures in the stand 51; Suitable means may be provided for adjusting the force of the springs so that each may be regulated to supply its proportionate share of the compressive force.

By-reason of this construction any desired gradually increasing compressive force may be applied to the molds as they progress along their path, furthermore the resistance" of the springs 55, 57, etc., permits sufficient I yielding of the compressor plate to avoidthe mannerdescribed in breakageof the mold if any hard substance accidentally gets between the mold faces.

a Inorderto remove the molded articles from the machine, an endless apron 61 is located beneath the path of the com ression mold member when it reaches disc arging position. The molded article, when discharged from the compression member, drops upon. the conveyen and is removed in my patent above referred to.

. In the operation of the machine, the oppositely disposed receiving mold faces which are carried by the radial arms 3 are dipped sucoessivelyinto the pulp in the vat. While immersed in the pulp, suction is applied through the hollow arm 3 and'the layer of pulp sucked up-upon the mold face. At this time the cams 23 act upon the compression mold arms to support them substantially at right angles to the arm 3 so that they do not enter the pulp in the vat. As soon as the mold emerges from the pulp in the vat, thecams 23 actuate the racks 21 and through them the gear segments 19 to cause the arms 17 to oscillate and to bring the compression members 16 into co iiperative relation to the receiving mold members. As

soon as the compression mold faces are closed upon the layers of pulp adhering to the receiving faces, the mold enters between the lower ends of the compressor plates 54. The rollers 60 upon the compression members of the mold then engage the compressor plates 54:. During the fur 'ther travel of the mold, the compressor plates exert a progressively increasing pressure upon the compression members of the mold thus slowly squeezing the water out of the molded article. Upon further movement of the mold, the compressed airnpipe 1 1 is supplied with compressed.- air and,

almost immediately afterward, the suction is cut off from the suction chamber so that any liquid or moisture remaining ni'the suction chamber or mold will be blown down the hollow arm 3. Y

The compressed air continues to act upon the mold after the same has passed beyond the compression plates and the cams 23 have started to withdraw the compression mold member from the receiving mold member.-

As the mold passes beneath the arm 41 itis engaged by the pin 40 which rides up upon the inclined surface 46 of said mold member until it reaches the aperture it drops into said aperture and imping ng upon the central portion 37 of the discharge .plate or spider actuates the latter to advance the peripheral portion of the mold face and to deliver the molded article uponthe conveyer, v

It is to be understood that the construc-' tion disclosed herein is illustrative but not restrictive and that the same may be modified within the meaning and scope of the 'claimswhich follow. e

v Having thus described my invention what I claim as new and desire to secure by ee.

ters Patent is: V

' 1. In a machine for molding pulp articles comprising a traveling mold having a plurality of separable members provided with coiiperating mold faces, and means for introducing a layer of pulp between said mold faces; a stationary compressor secured against movement with the traveling mold ducing a layer of pulp between said mold faces; a stationary compressor comprising plates extending in substantial parallelism with the path of the mold and a series of springs adapted to exert progressively increasing pressure upon said plates.

3. In a machine for molding pulp articles comprising a traveling mold havin a plurality of separable members provi ed with cooperating mold faces, and means for introducing a-layer of pulp between said mold faces; converging compressor plates backed by a series of resilient members of progressively increasing strength adapted to engage said mold members.

4. In a machine for molding pulp articles comprising a mold formed of a plurality of separable mold members having cooperating faces, means for causing said mold to travel in a circular path, and means for introducing a layer of pulp between said faces; a

stationary frame having an arcu-ate com-\ pressor plate curved to conform to the path of the mold located adjacent said path and secured against movement with the traveling mold and yieldable means for causing said compressor plate to apply a gradually increasing pressure to the mold members whereby the fluid will be gradually forced from the pulp.

5. In a machine for molding pulp articles comprising a mold having a pulp receiving member and a compression member, means for causing said members to travel in a circular path, means for introducing a layer of pulp between said members, a stationary frame having an arcuate compressor plate in the form of a quadrant conforming to the path of the mold and located adjacent said path, and yieldable means for forcin said compressor plate into engagement wit said compression mold member to cause a progressively increasing pressure to be applied to said mold during approximately a quarter of each cycle of its movement.

6. In a machine for molding pulp articles comprising a traveling mold formed of a plurality of separable mold members having cooperating receiving and compression faces, means for causing said mold to travel in a curved path and means for introducing a layer of pulp between the said mold faces, a stand curved to conform to the path of said mold located adjacent said path, a compressor plate similarly curved carried by said stand and a series of resilient members of progressively increasing strength intermediate of said' stand and sald compressor plate.

7. In a machine for molding pulp articles comprising a traveling mold formed of a plurality ofseparable mold members having cooperating receiving and compression faces, means for causing said mold to travel in a curved path and means for introducing a layer of pulp between the said mold faces, a

mold members to travel in a circular path,

means for supplying a layer of pulp to said mold receiving member, means for closing the compression members upon said layer of pulp and a frame havinga pair of oppositely disposed arcuate compressor plates extending in substantial parallelism with the path of the mold and converging in the direction of movement of said mold, and means for exerting a yieldable progressively increasing pressure upon said mold members through substantially, a quadrant of the movement of said mold.

- 9. In a machine for molding pulp articles comprising a traveling mold having a plurality of separable members provided with cooperating mold faces, and means for introduciflg a layer of pulp between said mold faces, a stationary compressor comprising plates extending in substantial parallelism with the path of the mold, springs adapted to exert progressively increasing pressure upon said plates and antifriction rollers carried by said mold members adapted to engage said plates. e

10. In a machine for molding pulp articles, a mold comprising separable receiving and compression members having cooperating mold faces the face of said compres sion member comprising a r1g1d central section and a peripheral movable section telescopically mounted upon said central section and an actuatingmember for said movable section, resilient means between said central section and said actuating member adapted normally to retain said molded sections in molding position, the back of said compression mold member being apertured to permit an impinging instrumentality to strike said, actuating member and thereby section and a peripheral movable section telescopically mounted upon said central 1 "section, an actuating member for said movable section and resilient means between said actuating member and said central sec-. tion adapted normally to retain said sec tions in molding position, and the back of said compression member being provided with a central aperture, means for introducing 'a'layer of pulp between said mold mem bers, means for forcing said mold members together to compress the mold between them and a spring actuated pin located in the path of the compression mold member adaptedto ride up upon the back of said member, to enter the aperture in the back of said compression member and impinge upon said actuating member and thereby cause the pe ripheral movable section to discharge the Ibnoldedarticle from said compression mem- 12; In a machine for molding pulp ar ticles comprising a traveling mold having a pulp receiving member and a compression member, said compression member being provided with a face having a rigid central section and a peripheral movable section telescopically mounted upon said central sec 5 tion, an actuating member for said movable section and resilient means between said actuating member and said central section adapted normally to retain said sections in molding position, the back of said compres- 40 sion member being provided with a central aperture, means for introducing a layer of pulp between said mold members, compression plates extending in the direction of travel of said mold adapted to engage said mold members, means for imposing upon said plates a progressively increasing pressure whereby the plate will be gradually expelled from the pulp, a spring actuated pin located in the path of the compressionmold member adapted to ride'up upon the back of said member to enter the aperture in the back of said mold member and impinge upon the actuating means for the peripheral movable section to cause the same to discharge the molded article from said compression member.

In testimony whereof, I have signed my name to this specification.

FRANK W. WATERMAN. 

